Previous processes for identifying multiple individual loads supplied by a common AC power service use measurements of electrical parameters of only the common supply. These parameters are digitally measured for each alternating current (AC) supply cycle, e.g., 60 samples per second in North America. The loads are identified using the time dependent behaviors (referred to herein as time traces) of the first few seconds of the turn-on positive transition of these parameters. Many conventional devices such as incandescent lights and heaters consume essentially constant power after the positive transition until the device is turned off, thus producing a negative transition. Provided none of the transitions occur too close together, the on-off state of multiple devices can be accurately determined, as well as the power, runtime, and energy consumed by each device. This process is referred to herein as a time trace disaggregation process (TTDP).
An important consideration in a TTDP is matching the time trace of a new positive transition with a similar previous time trace associated with a particular device. If no match is found, the new time trace is to be used as a template for a new device.
The process for matching must balance selectivity versus tolerance. If the match is too selective, then multiple devices will be created that represent the same physical device. If the process for matching is too tolerant, however, multiple physical devices will be associated with the same device in the TTDP.
Some devices produce very consistent time traces. For example, incandescent lights and heaters produce very consistent time traces. The time between cycles and the duration of a cycle have essentially no effect on the time trace for these devices.
Some devices are sensitive to operating conditions and produce time traces that vary significantly. For example, multiple slow-start florescent lights controlled by one switch typically produce inconsistent time traces. This is because each light flickers and turns on with a delay that depends on its temperature. The time trace produced by cold lights is usually significantly different from the time trace produced by warm lights. The lights generally take several minutes to fully cool after being turned off. So, if a light is turned on shortly after it was turned off, the time trace will be usually be significantly different.
Some buildings may have different devices that have similar characteristics, such as incandescent lights that use 40 watts, 60 watts, and 75 watts, for example. The matching process should be sufficiently selective to create separate devices for each different light power. However, if there is only a single device that produces a unique and highly variable time trace, then the matching should be very tolerant so that even imperfect time traces may be matched to the device.
Because of these considerations, the matching process must have an adaptable selectivity that can be adjusted based on the device type and the combination of devices served by the common supply. Current technologies provide no such processes.
Considering all of the process required to identify and track a single on-off cycle of a device, the match process requires the largest computing resource. Therefore, the computing resource required to perform an analysis generally depends on the efficiency of the matching process.